The present invention relates to a drive device for a two-shaft extruding machine.
A two-shaft extruding machine of the same general type to which the invention pertains has been disclosed, for example, in Japanese Utility Model Publication No. 202/1984. In this drive device, two driven shafts are disposed equidistantly from a drive shaft, and each of the three shafts is provided with a gear. The gears can be changed so that rotational states in the same direction and in the opposite direction can be realized. That is, the gear on a first of the driven shafts is always meshed with the gear on the drive shaft, while the gear on the second driven shaft can be selectively meshed with either the gear on the first driven shaft or the gear on the drive shaft. Thus, the second drive shaft can be made to rotate in a desired direction by mounting an appropriate gear thereon.
In the prior art two-shaft extruding machine drive device described above, however, there has been a problem that when the rotational direction of the screw (normally associated with the second driven shaft) is reversed, it is necessary to disassemble the drive device to replace the gear on the screw. Thus, although it is possible in such a drive device to change the rotational direction of the screw, much labor and time are required to change the gear, resulting in low productivity.
An object of the invention is therefore to solve the problem described above, that is, to provide a two-shaft extruding machine drive device in which the rotational direction of the screw can be changed easily and externally without disassembling the drive device.